Shortly before this week’s latest defeat for a proposed cyber-security bill in the U.S. Senate, news came that President Barack Obama in October signed a limited “secret directive” to prevent cyber-attacks on computer networks.

The Washington Post said the document signed by the President is “Presidential Policy Directive 20,” and lists standard procedures for government agencies, including the military, to combat cyber threats.

It will also lead to the Department of Defense coming up with new rules to “guide commanders on when and how the military can go outside government networks to prevent a cyber-attack that could cause significant destruction or casualties,” The Post added.

Obama’s staff is also working on an additional presidential directive on cyber security that will be a public executive order, news reports add.

Meanwhile, on Wednesday, a group of Senators, mostly Republicans, voted down a cloture vote for a more comprehensive cyber-security law. It was the second time Republicans blocked the bill, with many of them concerned that it would create excessive regulations for U.S. businesses.

The legislative defeats lead many observers to believe that Obama will soon release the public executive order on the issue – which will include some of the topics included in the defeated bill.

The vote on Wednesday likely ended the chance that Congress would approve a bill this year, Harry Reid, (D-Nev.), the Senate’s Majority Leader, said.

“Cyber security is dead for this Congress,” Reid said in a statement on the Senate floor following the bill’s defeat. “Whatever we do on this bill, it’s not enough for the Chamber of Commerce.”

The defeated bill, introduced by Joe Lieberman, (Ind. - CT), and Susan Collins, (R-Maine), called for voluntary cyber-security standards for businesses running such infrastructure as power grids and chemical plants, Bloomberg News said. The bill also called for more business and government to share information.

The U.S. Chamber of Commerce continues to be opposed to the bill. Some Republicans have supported a less-restrictive bill on the issue. Verizon, AT&T and some major utilities were among the companies opposed to the Lieberman-Collins bill, Bloomberg reported.

Meanwhile, there are repeated concerns that a major cyber-attack against the United States continues to be an imminent threat from foreign governments, terrorists or hackers. For instance, on Wednesday the National Academy of Sciences issued a report that the U.S. electric power system is vulnerable to acts of terrorism which could cause much more damage than Hurricane Sandy, “blacking out large regions of the country for weeks or months and costing many billions of dollars.”

In October, Defense Secretary Leon Panetta said in a public speech that a large cyber-attack “could be a cyber Pearl Harbor; an attack that would cause physical destruction and the loss of life.”

U.S. Gen. Keith B. Alexander, who heads up the National Security Agency (NSA), said earlier this year at the American Enterprise Institute, "If the critical infrastructure community is being attacked by something, we need them to tell us – at network speed.”

“It doesn't require the government to read their mail, or your mail, to do that,” he added in a statement carried by TechZone360.

The U.S. military set up a Cyber Command in 2010, and its leader, Gen. Alexander, wants specialized officers at Fort Meade to be given “greater latitude to stop or prevent attacks,” The Post said.

Meanwhile, a compromise bill is a long-shot during the current Congress.

But any executive order by the President, no matter how carefully crafted, will not be as comprehensive to what is needed, government officials warn.

“We are still going to need legislation to do the things that we think need to be done,” White House Cybersecurity Coordinator Michael Daniel told Bloomberg News. “An executive order is not an adequate substitute.”